The constellation of Scorpius (Latin for “scorpion”) lies in the western part of the Milky Way – is best seen from June to August, and was listed by the Greek astronomer Ptolemy in the second century AD.
The heart of Scorpius is the red giant star Antares …. the 15th brightest star in the sky. 550 light-years away with a diameter 400 times that of the Sun, and 10,000 times brighter than the Sun. Antares is a double star, with a hot blue fifth magnitude companion.
Shaula is the second brightest star in Scorpius – a triple star system, consisting of hot blue stars 365 light-years away.
The double star Beta Scorpii has blue-white components both hot, massive, blue-white stars at least ten times as massive as our Sun; both expected to end their lives as supernova explosions.
Theta Scorpii, Sargas, is the third brightest star in Scorpius, a yellow giant shining from a distance of 270 light-years.
Delta Scorpii, or Dschubba, is an erratic blue-white star, having brightened in 2000 to become a first magnitude star, the second-brightest in the constellation.
There are many globular clusters in Scorpius. M 4 can be seen with binoculars and is one of the closest globulars to the Sun, at 7,200 light-years away.
M6 and M7 are two bright open clusters which are naked eye objects. M6 is known as the “Butterfly Cluster”. M7, also known as Ptolemy's Cluster, is much larger and appears as a fuzzy spot against the Milky Way background. It appears twice the size of the moon, and was known to the Greek astronomer Ptolemy as early as 325 BCE.
NGC 6231 is a bright open star cluster located near Zeta Scorpii 5,900 light-years away, and belongs to the Scorpius OB association of very young stars.
IC 4604 (Rho Ophiuchi – in a previous post) is a large diffuse nebula of 5th magnitude located in the southwestern corner of the adjacent constellation Ophiuchus, surrounding the bright triple star Rho Ophiuchi. Several regions of bright and dark nebulosity surround this area.
Imaged 10 August 2013
Rokinon 14mm f/2.8 Prime piggy-backed on Celestron 9.25
16 x 20 sec exposures stacked in Deep Sky Stacker